The present invention relates to a storage case for packaging a recording medium disc having recorded therein a music, image or optically readable digital information for use in a computer.
One known prior art related to such storage cases for packaging recording medium discs such as CDs, DVDs and LDs is described in Japanese Examined Patent Publication No. HEI 6-51506 (corresponding to U.S. Pat. No. 4,874,085).
This prior art storage case is constructed to support a disc only at its central area free of information carrying tracks and not to contact the area containing information carrying tracks of the disc by providing a predetermined clearance therebetween, so as not to transfer any deformation of the case to the disc.
Thus, this construction requires that the case have a higher rigidity so as to minimize its possible deformation, and make such clearance relatively large. This results in a drawback that the case has a relatively large thickness.
The storage case having an increased thickness involves problems such as a larger storage space needed for such cases and more frequent replenishment of goods on display due to a decreased number of discs which are displayable at a time, for example, in displaying and selling.
Accordingly, a storage case of this type has been desired to have a decreased thickness.
To this end, the art of reducing such clearance by supporting a disc at its outer peripheral edge area as well as at its central area, has been developed as disclosed, for example, in Japanese Unexamined Patent Publication No. SHO 60-148485.
Though this art employs a structure for supporting the disc at both the central and outer peripheral areas thereof, other structures, particularly for holding the central hole portion of the disc, remain conventional and, hence, it is impossible to decrease the thickness of the storage case as desired.
Typically known such structure for holding the central hole portion of a disc is described, for example, in Japanese Examined Utility Model Publication No. HEI 3-31748.
This conventional structure includes a boss portion to be fitted into the central hole of the disc, the boss portion defining a multiplicity of radially extending slits which are circumferentially equally spaced from each adjacent one. These slits form elastic pieces adapted to support the central area of the disc elastically.
With this structure the projecting amount of the boss portion to project from the upper side of the disc held by the boss portion is required to be relatively large so as to prevent an unexpected removal of the disc from the boss portion. For this reason it has been difficult to make the storage case thinner.
Also, this central hole portion holding structure has been desired to allow the disc to be removed by a simple operation as well as to hold the disc securely.
Although this conventional structure is capable of securely holding the disc by means of the multiplicity of elastic pieces for elastically supporting the disc, the removal of the disc therefrom is not easy because an increased pressing force is required to depress the elastic pieces for the removal.
Further, since constantly biasing the periphery of the central hole of the disc with an increased pressing force for secure holding is likely to cause the disc to warp, the holding structure has been desired to support the disc with a smallest possible force.
This means that the structure for holding the central hole portion of the disc has been desired to satisfy incompatible requirements: holding the disc with a smaller force, holding the disc securely, and allowing the disc to be removed by a simple one-touch operation.
In view of these requirements a storage case has been devised having a reduced number of elastic pieces located at three circumferential points and enabling a one-touch removal of a disc, as disclosed, for example, in German Patent DE3425579.
In this conventional storage case, however, the inner ends of the three elastic pieces are connected to a disc-like push member and, hence, a force working on this push member also works on the three elastic pieces at the same time. Accordingly, an increased force is required to deform these elastic pieces.
In addition, this storage case requires a compressed elastic element, a nip protuberance and the like for ensuring a one-touch removal of the disc, which makes the construction more intricate, thus resulting in a difficulty in making the storage case thinner.
It is an object of the present invention to provide a storage case having a thickness of about a half of the thickness of a conventional storage case.
Another object of the present invention is to provide a storage case which is capable of holding a disc at its central hole portion with a reduced force, holding the disc securely, and allowing the disc to be removed therefrom by a one-touch operation.
Other objects of the present invention include: to ease the operations of opening and closing the storage case; to prevent the storage case from being damaged; to facilitate the removal of the storage case from a storage rack or the like; to simplify the construction of a mold for manufacturing the storage case; and so forth.
To attain the above objects, the present invention provides the following means.
That is, the present invention provides a recording medium disc storage case comprising a holding plate for covering a recording side of a recording medium disc having a central hole, the holding plate having a holding portion to be removably fitted into the central hole of the disc, the holding portion including a base extending from an inner periphery of a perforation defined centrally of the holding plate, extensions extending circumferentially from the base, and projections each radially outwardly projecting from an end portion of each of the extensions. The projections have respective tips defining a circular envelope having a diameter greater than that of the central hole of the disc, and the extensions have an outer diameter such as to be fitted in the central hole of the disc.
In this construction according to the present invention, each projection is located at a position circumferentially displaced from the base portion.
Preferably, the base includes a plurality of base portions circumferentially spaced a predetermined distance from one another which are inclined radially inwardly and axially upwardly from the inner periphery of the perforation of the holding plate, each of the extensions is concentrically extending in one circumferential direction from an inner end portion of each base portion and is formed at its end portion with a push portion extending radially inwardly, and each of the projections is located on an upper edge portion of the end portion of each extension.
In the above construction the base and the extensions are elastically deformably arranged such that when the holding portion is fitted in the disc, the projections are located on an upper side of the disc, while when the push portions are depressed, the projections move to a lower side of the disc.
With this construction, each projection is located at a position displaced radially, circumferentially and axially from the corresponding base portion, whereby the amount of move of each projection in response to a depression of the corresponding push portion can be maximized. This allows each projection to move from the upper side to lower side of the disc with ease. Further, since each projection operates independently of other projections in response to the depression of the corresponding push portion, only a very small force is required for such depressing operation. Thus, the disc can be fitted on and removed from the holding portion with extreme ease.
Preferably, the projecting amount of each projection is determined such that a click sound is produced upon fitting of the disc on the holding portion or upon release of the disc from its fitting condition by depressing the push portions. This feature enables the user to confirm the fitting and removal of the disc readily.
The projections are preferably disposed at circumferentially trisecting locations. While a smaller number of projections enables easier removal of the disc, the number of projections is not limited to three but may be two to six at circumferentially equally dividing locations.
It is preferred that the upper surfaces of the projections form a top surface of the holding portion, and that when the holding portion is fitted into the disc, the distance between the upper side of the disc and the top surface of the holding portion be not greater than the thickness of the disc. By determining the dimensions of the holding portion as such, it is possible to reduce the amount of move from the upper side to lower side of the disc required of each projection.
The outer diameter of the extensions is preferably such as to be fitted in the central hole of the disc with a slight backlash. By holding the disc with a backlash the disc can be prevented from deforming.
The holding plate preferably has a central support portion and a peripheral support portion for respectively supporting central and peripheral portions situated out of the recording area of the disc. By thus supporting the two portions of the disc it is possible to minimize the clearance between the recording surface of the disc and the confronting surface of the holding plate thereby making the whole storage case thinner.
The holding plate may have an upper face adapted to confront the disc and a reverse face on the opposite side of the upper face, the reverse face being flat except the area of the holding portion, the upper face being formed with a peripheral wall having a predetermined thickness and protruding from a peripheral area thereof and an arcuated wall having a predetermined thickness and protruding from an area adapted to surround the outer periphery of the disc. With this construction the peripheral wall and the arcuated wall provide a rib effect to enhance the rigidity of the holding plate. This also makes it possible to thin the holding plate.
Thus, according to the present invention it is possible to reduce the thickness of the holding plate from the reverse face thereof to the top surface of the holding portion to 4 mm or less.
The holding plate may be contained in an openable case. Alternatively, it is possible that a cover member is pivotally supported directly on the holding plate to form a storage case.
Specifically, the holding plate may pivotally support the cover member through a hinge portion for opening and closing the cover member.
The holding portion preferably has a top surface which abuts an inner surface of the cover member or defines a clearance less than the thickness of the disc therebetween when the cover member is in its closed position. This enables the storage case to have a thickness of not greater than 6 mm when the holding plate and the cover member are closed relative to each other.
The cover member is preferably larger than the holding plate so as to cover the holding plate completely. By making the cover member larger than the holding plate it is possible to prevent penetration of dust into the storage case effectively.
Preferably, the cover member has an outer peripheral edge which partially juts out from an outer peripheral edge of the holding plate when the cover member is in its closed position over the holding plate, and the jutting portion is provided with a finger hook portion. The provision of the finger hook portion allows the user to remove the storage case out of a custody rack by hooking the finger hook portion with a finger thereby facilitating the removal of the storage case from the custody rack.
It is preferred that the cover member have a free edge portion defining a notch on the opposite side of the hinge portion, and that a portion of the holding plate corresponding in position to the notch of the cover member in its closed position be provided with a finger engaging portion. This feature allows the user to catch the finger engaging portion with a finger for opening the cover member even though the storage case is thin, thereby facilitating the opening and closing of the storage case.
The holding plate and the cover member may have respective abutting portions which come to abut each other when the cover member is opened 180xc2x0 relative to the holding plate to maintain the open condition. These abutting portions may be configured to allow the holding plate and the cover member to further pivot relative to each other when a force is exerted to open the cover member further from the 180xc2x0 open condition.
The storage case with such feature is prevented from any damage even if it is opened with an unexpectedly large force. In contrast a conventional storage case is provided with a stopper for the storage case not to open more than 180xc2x0 and, hence, is subject to damage when it is opened with a large force.
The holding plate and the cover member may have hinge-connected edge portions hinged to each other on one side thereof, free edge portions on the other side, and upper and lower edge portions which are opposite to each other via the hinge-connected edge portions and free edge portions, the upper and lower edge portions of the holding plate and cover member each having a peripheral wall rising thicknesswise of the storage case, the peripheral wall of one of the holding plate and the cover member having a protuberance projecting therefrom, the corresponding peripheral wall of the other having a recess to be removably fitted over the protuberance when the cover member is closed, the holding plate and the cover member each having a communication aperture extending through the thickness thereof to open upon the protuberance or the recess.
The provision of the communication aperture enables the use of a two-part mold comprising upper and lower mold parts for manufacturing a plastic storage case thereby reducing the manufacturing time and cost required. It should be noted that a conventional mold for manufacturing a conventional storage case free of any such aperture is a four-part mold comprising upper and lower mold parts and right and left lateral mold parts.
Preferably, the peripheral wall of one of the holding plate and the cover member is formed with a positioning protrusion adjacent the protuberance or recess for fit in the counterpart peripheral wall of the other. Such a positioning protrusion optimizes the positioning of the cover member and holding plate relative to each other and the engagement between the recess and the protuberance thereby making the opening and closing operations smooth.
The hinge portion comprises a pair of hinge pieces protruding from one of the holding plate and the cover member, a hinge shaft projecting from each of opposing inner surfaces of the pair of hinge pieces, and a bearing portion provided on the other for removably and pivotally supporting the hinge shaft. The bearing portion defines a hole receiving a tip portion of the hinge shaft for rotation and a notch receiving a half of the circumference of a base end portion of the hinge shaft and exposing the other half of the circumference.
Unlike a conventional storage case which is subject to damage at its hinge portion, the storage case employing the hinge structure according to the present invention has an enhanced strength at the hinge portion thereof and hence is prevented from damage.
Preferably, the holding plate and the cover member have hinge-connected edge portions hinged to each other on one side thereof, free edge portions on the other side, and upper and lower edge portions which are opposite to each other via the hinge-connected edge portions and free edge portions, the upper and lower edge portions of the cover member each having a peripheral wall which rises thicknesswise of the storage case and formed with a label holding claw projecting from the peripheral wall, the cover member defining a communication aperture extending through the thickness thereof to open upon the label holding claw. The provision of the communication aperture enables the use of a two-part mold comprising upper and lower mold parts for molding the cover member and hence is advantageous in terms of manufacturing and cost rather than the use of a conventional four-part mold.
According to the present invention it is possible to provide a thinner storage case and allow the user to put and remove a recording medium disc into and out of the storage case with a single hand in a mere one-touch operation.